>> Alternatively, could we use the _PAGE_GNTTAB PTE flag that is used for >> debugging? Indeed, if we did this, could be obviate the need for the >> PTE-zapping hook, by instead catching the case where this flag is set, >> and unmapping the grant implicitly? > > Well, in the general case you don't have enough info to know which grant to > release (a single page can be granted multiple times).
You'll also get the mm and the addr which should make it sufficiently unique, so this looks like a doable approach to me. ptep_get_and_clear_full() in include/asm-x86/pgtable_32.h needs to be changed take care, but that should be possible to do and the change is local to x86 paravirt_ops, which looks much better to me than touching generic mm code. cheers, Gerd _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linux-foundation.org/mailman/listinfo/virtualization
